Device for spraying fuel into the cylinders of internal-combustion engines



June 1930. A. w. KRAMLING 1,766,389

DEVICE FOR SPRAYING FUEL INTO THE CYLINDERS OF INTERNAL COMBUSTION ENGINES Filed June 25, 1925 2 Sheets-Sheet l J n 1930. A. w. KRAML'ING 1,766,389

DEVICE FOR SPRAYING FUEL INTO THE CYLINDERS OF INTERNAL COMBUSTION'ENGINES Filed June 23, 1925 2 Sheets-Sheet 2 a I L! i I l @gwkw Patented June 24, 1936 PATENT OFFICE ADOLF WILHELM KRAMLING, OF BERLIN-SCHMABGENDORF, GERMANY DEVICE FOR SPRAYIN G FUEL INTO THE CYLINDERS F INTERNAL-COMBUSTION ENGINES Application filed June 23, 1925, Serial No. 39,133, and-in Germany July 1, 1924.

This invention relates to an injecting device for internal combustion engines wherein the injection of the liquid fuel into the working cylinder is effected by compressed air which is withdrawn in a preliminary compressed condition from the working cylinder and is further compressed in a separate compressing chamber by a positively moved auxiliary piston. The admission of the preliminary compressed air from the workin cylinder into the said compression cham er is mainly eifected through separate channels or passages of which the opening into the compression chamber is alternately closed and again opened by the auxiliary piston.

In addition the compression chamber communicates by another passage, the nozzle, with the working cylinder. According to my invention this passage or this nozzle connects the compression chamber without the interposition of a valve to the working chamber and I arrange the fuel supply at the point where the fuel meets the atomizing air flowing to the nozzle substantially on the compression stroke of the auxiliary piston, in such a manner as to the time of meeting that the supply of fuel takes place mainly during the compression stroke. In this manner it can be arranged that the flow of air in the nozzle can be brought into a permissible relation to the course of the supply of fuel which is important for controlling the combustion operation in the working cylinder.

Two examples of construction of my in- 36 vention will now be described with reference to the accompanying drawings wherein Figure 1 is a vertical section through the upper end of the cylinder of an internal combustion engine, shown somewhat diagrammatically and in which non-essential details have been omitted for the sake of clearness.

Figure 2 shows to a larger scale a similar section through the injecting device andv its drivein a second form of construction.

Similar parts and parts -concerning the same purpose are indicated in both figures by the same references.

In the example of construction according to Figure 1 the rotating cam 2 on the cam shaft 1 presses downwardly at a given mo- .The lever 5 acts by means of a rod 9 on the auxiliary piston 10 and by means of the rod 17 and the roller 16 mounted at its upper end on the fuel pump piston 18. The piston 10 is made hollow and receives a filling piece 30 the dimensions of which determine the area of the compression chamber 13. As the lever 5 acts on the piston 10 with a longer arm this will carryout a larger stroke than the fuel pump piston 18. Springs 6, 11 and 19 cause the lever 5 and the pistons 10 and 18 constantly to tend to return into their initial position as illustrated. The rod 17 is hinged to the fuel pump piston 18 and by means of a governor of the engine which is not shown, can be actuated by mechanism 34, 35 in such. a manner that thepoint of contact between the roller 16 and the lever 5 .may be at different distances from the ful- With various adjustcrum of the latter. ments of the rod 17 and the roller 16 in relation to the lever 5 the fuel pump piston 18 will carry out strokes of varying length, whilst the movement of the lever 5 and the stroke of the piston 10 remain constant, and thus supply different quantities of fuel. In this manner the power of the engine can be controlled. The operation when introducing the fuel into the working cylinder of the engine is as follows.

The chamber 13 is. filled during the upward movement of the working piston 25 through the passage 14 and the nozzle 15 with air at the pressure existing in the chamber 24. The cam 2 presses the lever 5 downwards so that the pistons 10 and 18 are operated.

During its movement the auxiliary piston 10 closes the opening of the passage 14 in the chamber 13 and commences to compress the air therein. As soon as the pressure of the air in the chamber 13 exceeds that of the air in the cylinder chamber 24 air passes out of the chamber 13 through the nozzle 15 into the chamber 24. During this operation the pump piston 18 forces a measured quantity of liquid fuel, which was drawn in during the previous upward movement of the piston 18 from the fuel supply pipe 21, gradually through the passage 22 into or in front of the nozzle 15. The fuel passing from the passage 22 is taken up by the passing air,

is atomized and injected into the chamber 24 where it is burnt. After the completion of the supply of fuel into the working cylin ders the pistons 10 and 18 and the lever 5 return to their original positions.

A screw 20 permits of limiting the upward stroke of the piston 18 in such a manner that before it commences its downward movement a free space is formed between the roller 16 and the lever 5 and the adjustment of the stroke of the piston 18 can be effected by the mechanism 34, 35 with a small consumption of power. The screw 7 limits the upward movement of the lever 5. The nut 12 which is adjustable parallel to the axis of the piston 10 limits the upward movement of'this latter piston. Plugs 31 and 32 permit of ready access of the passage 14 so that this can be cleaned easily.

In the construction according to Figure 2 only the operating mechanism for the auxiliary piston 10 is illustrated. In this case the pump piston can be moved by separate driving means so that a great freedom as regards relative proportions of their movement can be obtained. The compression chamber 13 is located in an easily exchangeable insertion 26 of the cylinder body 23. The air flowing through the passage 14 to the chamber 13 comes directly in contact with the water cooled wall of the body 23 and is thus cooled. The insertion 26 is separated from the cooling chamber 23 by a closed wall 23' and can be removed without the necessity of removing the cooling water.

The nozzle 15 and the passage 27 located in front thereof are provided in exchangeable fittings in the part 26. By inserting or removing plates 28 between the piston 10 and a member 29 actuated by the driving member 9 the edge of the piston 10 which controls the passage of air from the piston 14 into the chamber 13 can be arranged lower or higher. The piston 10 may be. asin the form ofinvcntion illustrated in Fig. 1, hollow. By inserting a filling piece 30 of suitable dimensions the size of the hollow space and, as this forms a part of the compression chamber 13, also the size of the compression chamber can be varied and thus the obtainable highest pressure of the atomizing air can be adjusted in a simple manner.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. In an internal combustion engine the combination with a working cylinder and a piston therein, and a fuel injecting device comprising in combination a compression chamber, two separate means of communication between the compression chamber and the cylinder, one of said means establishing permanent communication between the compression chamber and the cylinder, an auxiliary piston in the said compression chamber, a fuel supplying pump, a piston in the said pump, means for driving the said pump piston and the said auxiliary piston, the said pistons being separately actuated by the said driving means, said auxiliary piston being adapted to control the second means of communication between the compression chamber and the working cylinder, the arrangement being such that during the compression stroke of the piston in the working cylinder air from said cylinder is forced into the compression chamber and is further compressed therein by the auxiliary piston in the compression chamber whilst fuel is supplied outside of the piston in the said compression chamber into the air flowing from the said chamber to the said cylinder during the compression stroke of the said piston in the compression chamber.

2.111 an internal combustion engine the combination with a working cylinder and a piston therein and a fuel injecting device comprising in combination a compression chamber, two separate means of communica tion between the compression chamber and the cylinder, one of said means establishing permanent communication between the compression chamber and the cylinder, an auxiliary piston in the said compression chamber, a fuel supplying pump, a piston in the said pump, a pivotally supported lever for driving the said pump piston and the said auxiliary piston, the said pistons being actuated by the said lever with different lever length, said auxiliary piston being adapted to control the second means of communication between the compression chamber and the working cylinder, the arrangement being such that during the compression stroke of the piston in the working cylinder air from said cylinder is forced into the compression chamber and is further compressed therein by the auxiliary pistonin the compression chamber whilstfuel is supplied into the air, flowing from the said chamber to the said cylinder during the compression stroke of the said piston in the compression chamber.

3. In an. internal combustion engine the combination with a working cylinder and a piston therein, and a fuel injecting device comprising in combination a fuel supply pump and a compression chamber, two separate means of communication between the compression chamber and the cylinder, one of said means establishing permanent communication between the compression chamber and the cylinder, an auxiliary piston in said compression chamber being adapted to control the other one of said means of communication, a cylindrical bore leading from the said chamber to the atmosphere, a plunger tightly fitting into and closing the said bore, and outer positive driving means retaining the said plunger in the said cylindrical bore.

4. ln an internal combustion engine the combination with a working cylinder and a piston therein, of a compression chamber, two separate means of communication between the compression chamber and the cylinder, one of said means establishing permanent communication between the compression chamber and the cylinder, a hollow piston in the compression chamber,-an adjustable fill ing member inside said hollow piston, said filling member being adapted to vary the maximum pressure obtainable in the compression chamber, means for actuating the piston in the compression chamber, said last mentioned piston being adapted to control the second means of communication between the compression chamber and the cylinder, and means for the supply of fuel to the last mentioned means of communication.

5. In an internal combustion engine the combination with a working cylinder and a piston therein, of a compression chamber, two separate means of communication between the compression chamber and the cylinder, one or" said means establishing permanent communication between the compression chamber and the cylinder, a piston inside the compression chamber, spring means adapted normally to withdraw the piston from the compression chamber, means for limiting the movement of said piston, a fuel supply pump, a lever for actuating the fuel supply pump and the piston in the compression chamber, the fuel supply pump being disposed nearer to the fulcrum of the lever than the piston in the compression chamber, and cam mechanism for actuating said lever.

6. In an internal combustion engine the combination with a working cylinder and a piston therein, of a compression chamber, two separate means of communication between the compression chamber and the cylinder, one of said means establishing permanent communication between the compression chamber and the cylinder, a piston inside the compression chamber, spring means adapted normally to withdraw the piston from the compression chamber, means for limiting the movement of said piston, a lever pivotally mounted at one end, a bracket in which said lever is pivoted, the free end of said lever being adapted to actuate the piston in the compression chamber, said last mentioned piston being adapted to control the second means of communication between the compression chamber and the cylinder, adj ustable means for limiting the movement of said lever in one direction, cam mechanism for actuating said lever, and means for supplying fuel to the said second means of communication.

7. In an internal combustion engine the combination with a working cylinder and a piston therein, of a compression chamher, two separate means of communication between the compression chamber and the cylinder, one of said means establishing permanent communication between the compression chamber and the cylinder, a piston inside the compression chamber, spring means adapted normally to withdraw the piston from the compression chamber, means for limiting the movement or said piston, a bracket mounted on the engine, a lever pivotally mounted at one end in said bracket, a fuel supply pump, means for limiting the stroke of said pump, said lever being adapted to actuate the piston in the compression chamber and the fuel supply pump, the fuel supply pump being arranged nearer to the pivot of said lever than the piston in the compression chamber, spring means for returning the pump, adjustable means for limiting the movement of the lever in one direction, and cam mechanism for actuating said lever.

In testimony whereof I have afiixed my signature.

ADOLF WlLHEL-M KRi ill lLlNG. 

